FORBIDDEN SKY
We live in a place we call 'The Pale'. Deep below, between the mountains, carved out caverns into castles. We had to adapt, and so we did.
The sky was torched. the protective layers of the atmosphere stripped away. any exposure would melt a man's skin clean off in seconds. This act was done in an attempt to exterminate us, but we were resiliant.
We learned how to see in the dark, adapted the eyes for it. We engineered plants to grow, and automated the process... keeping us fed. We built water extractors, geothermal powerplants, artifical light... still, nothing could match the real thing.
Now three generations later and most of us have never even seen the open world. The open space would probably make them nervous. Besides, there is nothing left for us out there.